Construction jobsites typically contain a variety of elements such as equipment, power lines, structures, building materials, and personnel. Depending on the phase of a project, there are changing arrangements of these elements while the building project itself progresses toward completion. During any given phase, however, a crane operator is required to take safety precautions so as not to run the boom into obstacles during operation of the crane. To do so, the crane operator often requires another worker on the ground that spots and watches for any impending problems, such as coming too close to an obstacle. This worker may then signal to the crane operator to move away from the obstacle or to shut the crane down. This includes inefficiencies and the need to pay the worker for just monitoring crane function visually.
The ability to alter crane functions with respect to defined areas or forbidden zones within the operational radius of cranes has been made generally available to the construction industry. This capability has evolved as the use of electronics and software for control systems has progressed. This capability is utilized in an operator aid device that can be referred to as a Working Range Limiter or WRL. When a WRL typically defines a forbidden zone it is seen as a map as viewed from above the jobsite.
A traditional WRL is useful for avoiding obstacles when the obstacles occur in the plane of movement, but fails when the geometry becomes more complicated. For example, if a building is marked as a forbidden zone to prevent a boom from impacting the building, a mobile crane will never be able to lift a load to the top of the building because to do so necessarily entails a portion of the crane entering the forbidden zone. If instead, the building is not designated as being in the forbidden zone, the crane could accidently swing into building when swinging the boom.
It would be beneficial to develop a system that inhibits collisions between a crane and obstacles like a traditional WRL system, while allowing the crane to extend into what would traditionally be considered a forbidden zone.